Azaphospholenes and use thereof

ABSTRACT

The invention relates to azaphospholenes of the type ##STR1## wherein R 1  and R 2  may be alkyl, aryl and aralkyl groups, processes for preparing same and the use thereof.

This is a continuation-in-part of application Ser. No. 335,021, filedApr. 7, 1989, now abandoned, which is a continuation of application Ser.No. 054,343, filed May 26, 1987, now abandoned.

It has been known that olefins can be dimerized or co-dimerized by meansof nickel-containing and phosphane-modified catalysts. Thus, theco-dimerization of cyclic dienes or strained olefins such as norborneneand ethene by using π-allylnickel halides or nickel(O) compounds and theactivation thereof by means of Lewis acids and the modification withacyclic phosphanes, also optically active acyclic phosphanes, have beendescribed several times [German Pat. No. 20 39 125, StudiengesellschaftKohle mbH. (priority 1970); U.S. Pat. No. 3,978,147, StudiengesellschaftKohle mbH. (priority 1973); U.S. Pat. No. 4,098,834, StudiengesellschaftKohle mbH. (priority 1976); G. Wilke et al., Angew. Chem. 1972, 1070; B.Bogdanovic et al., Angew. Chem. 1973, 1013; F. Petit et al., Bull. Soc.Chim. 1979, II-415; J. Chem. Soc. 1980, 937; G. Buono et al., J. Org.Chem. 1985, 50, 1781]. The processes known so far have technicaldisadvantages, as the catalysts show only relatively low activities andmoreover, the accomplished selectivities are insufficient. The maximumnumbers of catalytic cycles attainable with the processes described sofar are too low for a commercial use.

Surprisingly, it was now found that said technical defects of theprocesses known so far can be overcome by using azaphospholenes asmodifying ligands, the substituents of which azaphospholenes, due totheir spatial requirements, will block certain rotations in the catalystcomplexes. Therefrom ensue relatively rigid arrangements at the catalystwherein always one nickel atom is complexed to each phosphorus atom.Such ligands are phospholenes having the following structure: ##STR2##wherein the moieties R₁ and R₂ may be alkyl, aryl and aralkyl groupswhich may be varied within wide limits. Upon the preferred selection of##STR3## preferably in the optical R- or S-forms, respectively, and R₂=CH₃, particularly good results are obtained. The up to now unknowndiastereomer built up with these substituents has the followingstructure and configuration according to x-ray structural analysis:##STR4##

This diastereomer 6a was obtained by the following route starting from(-)-α-pinene or [(-)-(1R,5S)-myrtenal 1] and (+)-R-α-phenylethylamine 2.##STR5##

In an analogous manner, starting from (+)-α-pinene and(-)-S-α-phenylethylamine there may be prepared the compound 6a' which isthe enantiomer of the afore-mentioned diastereomer. 6a and 6a' asligands in nickel-containing catalysts have the effect that, e.g., theco-dimerization of norbornene with ethene may be realized even at atemperature of from +60° C. to -120° C., and preferably of from -20° C.to -80° C., with an activity of 20,000 cycles per hour and selectivitiesof >90%. The (-)-exo-vinylnorbornane formed according to the followingreaction equation ##STR6## by the use of 6a as ligand in the nickelcatalyst in CH₂ Cl₂ has an enantiomeric excess (e.e.) of 57%, i.e. theligand 6a causes not only high activity and selectivity, but also a highoptical induction, so that according to the process an optically activeproduct is obtained 78.5% of which consist of on enantiomer.

If, contrary thereto, an analogous phospholene is built up starting from(-)-α-pinene and (-)-S-α-phenylethylamine, then another diastereomer 6bresults therefrom, the structure of which was also elucidated by X-rayanalysis. ##STR7##

6b, as a catalyst component shows the effects as indicated above for 6awith respect to catalyst activity to a degree reduced by the factor 100,i.e. under the same conditions there are accomplished about 200 cyclesinstead of 20,000 cycles. Then the obtained product shows (+)-rotationand is (+)-exo-vinylnorbornane with an e.e. of 40%. Molecular modellinginvestigations on 6a and 6b show that in 6a rotations around certainbonds, e.g. the central C--C bond (C₁ -C₃₀) are largely restricted,while this is not the case in 6b. In 6a therefrom result the rigidarrangements as mentioned which correspond to secondary structures inenzymes.

SYNTHESIS OF AZAPHOSPHOLENE(1R,5S)-6,6-Dimethyl-2-[(1R)-1-N-phenylethylazamethino]bicyclo[3.1.1]hept-2-ene3

34.37 g (0.284 mol) of (+)-(1R)-phenylethylamine 2 are charged in a 250ml flask and heated to 70°-80° C. At this temperature 42.94 g (0.286mol) of (-)-(1R,5S)-myrtenal 1 are dropwise added within 1 h. Atwo-phase mixture is formed stirring of which is continued for 1 h.After cooling to room temperature 50 ml of ether are added, the aqueousphase is separated (4 ml), and the organic phase is dried with KOH/Na₂SO₄. Then the ether is condensed off, and the crude product 3 isdistilled under high vacuum.

Yield: 62.3 g (86.7% of theory); b.p. 108°-112° C.

5-Bromo-5,9,9-trimethyl-4-[(1R)-1-phenylethyl]-4-aza-5-λ⁴-phosphoniatricyclo-[6.1.1¹.8.0².6 ]-dec-2(3)-ene bromide 4a,5-Bromo-5,9,9-trimethyl-4-[(1R)-1-phenylethyl]-4-aza-5-λ⁴-phosphoniatricyclo-[6.1.1¹.8.0².6 ]-dec-2(6)-ene bromide 4b

49.40 g (0.195 mol) of the azadiene 3 in 700 ml of n-pentane arecharged, and 40.14 g (0.195 mol) of MePBr₂ in about 200 ml of n-pentaneare dropwise added. A yellow precipitate is immediately formed. Afterthe MePBr₂ addition, the reaction mixture is stirred for 4 days. Thenthe yellow solid (crude phosphonium salts 4) are filtered off, washedthree times with 100 ml of n-pentane each and dried in vacuo.

Yield of crude material: 75.1 g (84.0% of theory). (δ) ³¹ P-NMR: 4a 77.2ppm (CD₂ Cl₂); 4b 67.1 ppm (CD₂ Cl₂).

Bis-(3R)-3-{(1R,5R,8R)-5,9,9-trimethyl-4-[(1R)-1-phenylethyl]-4-aza-5-phosphatricyclo-[6.1.1¹.8.0².6]-dec-2(6)-enyl} 6a

10.05 g (21.9 mmol) of the crude product 40 are suspended in 100 ml ofTHF on a frit, the filtrate is collected in a flask, and the residue isdiscarded. To the orange-colored filtrate there are added at -10° C.0.66 g (272 mmol) of active magnesium portionwise under vigorousstirring. After the completion of the addition the batch is allowed towarm up slowly to room temperature and is stirred overnight. After thesolvent has been condensed off, 200 ml of ether are added to theresidue, and the mixture is filtered. The ether is condensed off fromthe yellow filtrate to obtain 10.62 g of a viscous residue which isdissolved in 4 to 5 parts by volume of methanol with heating to about60° C. In a water bath (about 60° C.) the mixture is stirred and allowedto cool to room temperature overnight. A colorless precipitate of 6a isformed.

Yield: 0.84 g (12.9% of theory); m.p. 134°-135° C. (recrystallized fromethanol).

(δ) ³¹ P-NMR: 49.9 ppm (toluene); [α]⁵⁸⁹ =-64.69° (0.64 g/100 ml of CH₂Cl₂).

The azaphospholenes of the type 6a are suitable for the preparation ofcatalysts of a highly selective activity which in turn are capable ofconverting unsaturated hydrocarbons into optically active compounds.Thus, an optically active vinyl bicycloheptane is obtained frombicycloheptene and ethylene in space-time yields not yet described sofar. Said optically active vinyl bicycloheptane in turn may be thestarting material for the terpolymerization together with, e.g.,ethylene and propylene to give polymers, and more particularly opticallyactive polymers. Optically active polymers, due to their high stericalregularity, have improved physical and mechanical properties. Thus,optically active polymers are suitable as absorbents for the separationof enantiomers. In the same manner, an optically active 3-phenylbutene-1is selectively obtainable in high yield from styrene and ethylene byco-dimerization, and so are substituted 3-phenylbutenes-1 fromsubstituted styrenes and ethylene. The polymerization of α-olefinproducts to optically active polymers is effected in the same way as theterpolymerization set forth above.

In the practice of the invention there can be used styrene per se aswell as substituted and/or benzofused styrenes, e.g. 4-isobutyl-styrene,benzostyrene (vinylnaphthalene), 2-methoxy-6-vinyl-naphthalene, andother alkyl, halo, alkoxy and like styrenes and vinylnaphthalenes.

A further application of the azaphospholenes in the form of thedescribed complex compounds together with organoaluminum compounds isthe selective change of the structure of, e.g., heptadiene-1,6 to form1-methyl-2-methylidene-cyclopentene, as well as the co-dimerization of1,3-cyclopentadiene and ethylene leading to optically active3-phenylpentene-1.

Catalytic Synthesis of Vinyl Bicycloheptane EXAMPLE 1

A 2-l four-neck flask equipped with stirrer, dropping funnel and aClaisen head with thermometer is evacuated with heating and filled withargon. The flask is charged with 600 ml of CH₂ Cl₂, and the droppingfunnel is filled with 600 ml of a CH₂ Cl₂ solution of 400 g (4.25 mol)bicyclo[2.2.1]heptene. The flask is cooled to -65° C. while its contentis stirred, and 0.047 g (0.108 mmol) of π-allylnickel chloride/phosphane6a complex (Ni:P=1:1) dissolved in about 10 ml of cooled CH₂ Cl₂ and0.239 ml (1 mmol) of Et₃ Al₂ Cl₃ (P:Ni:Al=1:1:20) are added, whereuponthe complex solution becomes violet in color. After briefly evacuatingwith an oil pump, the vacuum is removed with dry ethylene, and thesolution of bicycloheptene is dropwise added with stirring within 60minutes. In the course thereof a high heat evolution is observed. Duringthe reaction period (90 minutes) ethylene is introduced into theapparatus whereby the reaction temperature is increased to -58° C.

Then the reaction is terminated by introducing gaseous ammonia, and theproduct is condensed off in vacuo. From the condensate thus obtained thesolvent is distilled off under normal pressure, and the residue isdistilled through a Vigreux column.

Yield: 384 g (74% of theory).

(-)-exo-2-vinyl bicyclo[2.2.1]heptane (54% e.e.); conversion number:29,140.

[α]_(max) ²² =(±) 51°; b.p. 54° C./30 mbar; D²⁰ =0.8726 g/cm³.

EXAMPLE 2

The procedure is as in Example 1, using a 0.5-l four-neck flask. Theflask is charged with 150 ml of CH₂ Cl₂, and the dropping funnel isfilled with 30 ml (0.32 mol) of bicyclo[2.2.1]heptene in 50 ml of CH₂Cl₂. The solvent is cooled to -70° C., and 0.0961 g (0.352 mmol) ofbis-cyclooctadienenickel and 0.105 g (0.352 mmol) of the phosphane 6aare added. The reaction mixture is allowed to warm up slowly to -15° C.,until a strongly yellow clear solution, is formed, and then is againcooled to -70° C., and 0.080 ml (0.352 mmol) of Et₃ Al₂ Cl₃(P:Ni:Al=1:1:2) are added. After renewed heating to -20° C. the solutionis saturated with ethylene, and the solution of bicycloheptene isdropwise added within 15 minutes. The reaction mixture is kept saturatedwith ethylene by vigorous stirring for 60 minutes. The reaction isterminated with gaseous ammonia. The product is condensed off, thesolvent is withdrawn, and the residue is distilled through a Vigreuxcolumn about 30 cm in length.

Yield: 35 g (90% of theory).

(-)-exo-2-vinyl bicyclo[2.2.1]heptane (8.2% e.e.); conversion number:815.

EXAMPLE 3

The procedure is as in Example 1. A 1-liter flask is charged with 500 mlof chlorobenzene, and the dropping funnel is filled with 30 g (0.32 mol)of bicycloheptene in 50 ml of chlorobenzene. The chlorobenzene isstirred and cooled to -40° C., and 0.090 g (0.186 mmol) ofπ-allylnickel/phosphane-6a complex in about 15 ml of cooledchlorobenzene and 0.135 g (1.12 mmol) of Et₂ AlCl (P:Ni:Al=1:1:6) areadded thereto. Then the solution of bicycloheptene is dropwise addedwithin about 15 minutes, and ethylene is introduced into the apparatus.In the course of 2 h the reaction mixture is heated to +40° C.

The catalysis is terminated by introducing gaseous ammonia, and theproduct is condensed off in vacuo. From the condensate thus obtained thesolvent is distilled off under normal pressure, and the residue isdistilled through a Vigreux column.

Yield: 34 g (87.5% of theory).

(+)-exo-2-vinyl bicyclo[2.2.1]heptane (10.8% e.e.); conversion number:1498. Thus, in chlorobenzene the formation of the (+)-form is preferred.

EXAMPLE 4

The procedure is as in Example 1. A 0.5-l flask is charged with 150 mlof CHCl₃, and the dropping funnel is filled with 30 g (0.32 mol) ofbicycloheptene in 50 ml of CHCl₃. The solvent is cooled to -30° C., and0.020 g (0.114 mmol) of nickel acetate and 0.0678 g (0.228 mmol) ofphosphane 6a are added. The reaction mixture is stirred for 30 minutesat -30° C., and then 0.133 g (0.684 mmol) of AgBF₄ (P:Ni:BF₄ =2:1:6) areadded. After stirring for another 30 minutes the solution ofbicycloheptene is dropwise added within 10 minutes, and ethylene issimultaneously introduced into the apparatus. After 60 minutes thereaction is terminated by introducing gaseous ammonia. The product iscondensed off, the solvent is withdrawn, and the residue is distilled.

Yield: 32 g (85% of theory).

(-)-exo-2-vinyl bicyclo[2.2.1]heptane (29% e.e.); conversion number:2300.

EXAMPLE 5

The procedure is as in Example 1. A 0.5-l flask is charged with 150 mlof CH₂ Cl₂, and the dropping funnel is filled with 15 g (0.16 mol) ofbicycloheptene. The solvent is stirred and cooled to -72° C., and 0.287g (0.66 mmol) of π-allylnickel/phosphane-6b complex in about 20 ml ofcooled CH₂ Cl₂ and 0.150 ml (0.66 mmol) of Et₃ Al₂ Cl₃ (p:Ni:Al=1:1:2)are added thereto, whereby the complex solution becomes violet in color.Then at -72° C. the solution of bicycloheptene is dropwise added within30 minutes, and ethylene is simultaneously introduced into the solution.Upon completion of the bicycloheptene addition, the introduction ofethylene is continued for another 30 min. The reaction is terminated byintroducing gaseous ammonia, and the product is condensed off in vacuo,the solvent is withdrawn, and the residue is distilled.

Yield: 18 g (92% of theory).

(+)-exo-2-vinyl bicyclo[2.2.1]heptane (38% e.e.); conversion number:224.

EXAMPLE 6

The procedure is as in Example 1. A 0.5-l flask is charged with 150 mlof CH₂ Cl₂, and the dropping funnel is filled with 18 g (0.19 mol) ofbicycloheptene in 20 ml of CH₂ Cl₂. The solvent is stirred and cooled to-30° C., and 0.283 g (0.946 mmol) of the mixture of the phosphaneisomers 5a and 5b and 0.128 g (0.473 mmol) of bis-π-allylnickel chlorideare added. The reaction mixture is stirred for 30 minutes and thencooled to -70° C., and 0.454 ml (1.892 mmol) of Et₃ Al₂ Cl₃(P:Ni:Al=1:1:4) are added thereto. After briefly evacuating with an oilpump, the vacuum is removed with dry ethylene, and the solution ofbicycloheptene is dropwise added within 15 minutes. Then theintroduction of ethylene into the apparatus is continued for another 15min. The reaction is terminated by introducing gaseous ammonia, theproduct is condensed off in vacuo, the solvent is withdrawn, and theresidue is distilled.

Yield: 6 g (26% of theory).

(-)-exo-2-vinyl bicyclo[2.2.1]heptane (3.4% e.e.); conversion number:52.

EXAMPLE 7

The procedure is as in Example 1. A 0.5-l flask is charged with 150 mlof CH₂ Cl₂, and the dropping funnel is filled with 30 g (0.32 mol) ofbicycloheptene in 50 ml of CH₂ Cl₂. The solvent is cooled to -65° C.,and 0.086 g (0.197 mmol) of π-allylnickel chloride/phosphane-6a complexdissolved in 10 ml of cooled CH₂ Cl₂ and 0.227 ml of Et₃ Al₂ Cl₃ areadded. The reaction mixture is stirred at -65° C. for 15 minutes. Then0.118 g (0.394 mmol) of the phosphane 6a (P:Ni:Al=3:1:10) are added, andthe solution is stirred for another 10 minutes. Then the solution ofbicycloheptene is dropwise added within 15 minutes, and ethylene issimultaneously introduced into the apparatus. The reaction is terminatedby introducing gaseous ammonia, the product is condensed off in vacuo,the solvent is withdrawn, and the residue is distilled.

Yield: 34 g (87% of theory).

(-)-exo-2-vinyl bicyclo[2.2.1]heptane (57% e.e.); conversion number:1413.

EXAMPLE 8

A 100-l glass reaction vessel equipped with stirrer, a 25-l feed tankand an internal thermometer is provided with an argon atmosphere. Thereaction vessel is charged with 50 l of CH₂ Cl₂, and the feed tank isfilled with 10.13 kg (107.7 mol) of bicycloheptene in 10 l of CH₂ Cl₂.The charged solvent is cooled to -40° C. by means of a refrigeratingmachine, and the bicycloheptene solution is cooled to -13° C.

Then ethylene is introduced, and 23 ml (0.102 mol) of Et₃ Al₂ Cl₃ and4.448 g (0.0127 mol) of π-allylnickel chloride/phosphane-6a complexdissolved in 50 ml of CH₂ Cl₂ (P:Ni:Al=1:1:20) are added. Then, withsimultaneous introduction of ethylene, the solution of bicycloheptene isallowed to run in within 6 hours. With full output of the connectedrefrigerating machine the reaction temperature increases to -31° C.After 6.5 h the reaction is terminated by the introduction of gaseousammonia. Then the solvent is distilled off under normal pressure, andthe residue is fractioned through a column.

Yield: 8.0 kg (65.6 mol; 60.9% of theory)

(-)-exo-2-vinyl bicyclo[2.2.1]heptane (32.6% e.e.); conversion number:6388.

Catalytic Synthesis of Optically Active 3-Phenylbutene-1 EXAMPLE 9

A 2-l four-neck flask equipped with stirrer, dropping funnel and aClaisen head with thermometer is evacuated with heating and filled withargon. The flask is charged with 700 ml of CH₂ Cl₂, and the droppingfunnel is filled with 460 ml of a CH₂ Cl₂ solution cooled to -30° C. of275 g (2.65 mol) of styrene. The flask is cooled to -70° C. while itscontent is stirred, and 0.590 g (1.36 mmol) of π-allylnickelchloride/phosphane 6a complex (Ni:P=1:1) dissolved in about 15 ml ofcooled CH₂ Cl₂ and 0.70 ml (3.0 mmol) of Et₃ Al₂ Cl₃ (P:Ni:Al=1:1:3) areadded. After briefly evacuating with an oil pump, the vacuum is removedwith dry ethylene, and the solution of styrene is dropwise added withstirring within 45 minutes. In the course thereof the solution becomeswarmed up to -60° C. During the reaction period (150 minutes) ethyleneis introduced into the apparatus. The catalysis is terminated byintroducing gaseous ammonia, and the product is condensed off in vacuo.From the condensate thus obtained the solvent is distilled off undernormal pressure, and the residue is distilled through a Vigreux column.

Yield: 340 g (97% of theory).

(-)-(R)-3-phenylbutene-1 (93% e.e.); conversion number: 1890.

EXAMPLE 10

The procedure is as in Example 1, using a 0.5-l four-neck flask. Theflask is charged with 150 ml of CH₂ Cl₂, and the dropping funnel isfilled with 18 g (0.17 mol) of styrene in 30 ml of CH₂ Cl₂. The solventis cooled to -70° C., and 0.0553 g (0.13 mmol) of π-allylnickelchloride/phosphane 6a complex in about 15 ml of cooled CH₂ Cl₂ and 0.030ml (0.13 mmol) of Et₃ Al₂ Cl₃ are added. Thereafter the reaction mixtureis warmed up to 0° C. within 60 minutes. At 0° C. the solution ofstyrene is dropwise added within 15 minutes, and ethylene is introducedinto the apparatus. The reaction is terminated by introducing gaseousammonia, and the product is condensed off in vacuo. Then, the solvent iswithdrawn, and the residue is distilled.

Yield: 20.9 g (93% of theory).

(-)-(R)-3-phenylbutene-1 (76% e.e.); conversion number: 1216.

EXAMPLE 11

The procedure is as in Example 1, using a 0.5-l four-neck flask. Theflask is charged with 150 ml of toluene, and the dropping funnel isfilled with 20 g (0.19 mol) of styrene in 40 ml of toluene. At roomtemperature 0.120 g (0.44 mmol) of bis-cyclooctadienenickel and 0.131 g(0.44 mmol) of the phosphane 6a are added. The reaction mixture isstirred for 30 minutes, and then 0.106 g (0.88 mmol) of Et₂ AlCl(P:Ni:Al=1:1:4) are added. Then the solution of styrene is dropwiseadded within 30 minutes, and ethylene is introduced into the apparatus.By way of vigorous stirring the reaction mixture is kept saturated withethylene for 4 hours. The catalysis is terminated by the addition ofethanol, and the product is condensed off in vacuo. From the condensatethe solvent is distilled off through a Vigreux column under normalpressure, and the residue is fractionated under vacuum.

Yield: 15.1 g (60.2% of theory).

(-)-(R)-3-phenylbutene-1 (53% e.e.); conversion number: 260.

EXAMPLE 12

The procedure is as in Example 1. A 0.5-l flask is charged with 150 mlof CH₂ Cl₂, and the dropping funnel is filled with 20.3 g (0.195 mol) ofstyrene in 20 ml of CH₂ Cl₂. The solvent is cooled to -60° C. withstirring, and 0.0529 g (0.122 mmol) of π-allylnickel bromide/phosphane6a in 20 ml of cooled CH₂ Cl₂ and 0.028 ml (0.122 mmol) of Et₃ Al₂ Cl₃(P:Ni:Al=1:1:2) are added. After warming up to room temperature (+22°C.) the catalyst solution is saturated with ethylene, and the solutionof styrene is dropwise added within 15 minutes. The reaction mixture iskept in contact with ethylene by vigorous stirring for 30 minutes. Thenthe reaction is terminated by introducing gaseous ammonia, and theproduct is condensed off in vacuo. From the condensate thus obtained thesolvent is withdrawn, and the residue is distilled.

Yield: 24.7 g (96% of theory).

(+)-(S)-3-phenylbutene-1 (70% e.e.); conversion number: 1533.

EXAMPLE 13

The procedure is as in Example 1. A 0.5-l flask is charged with 150 mlof CH₂ Cl₂, and the dropping funnel is filled with 20 g (0.196 mol) ofstyrene in about 30 ml of CH₂ Cl₂. The solvent is cooled to -30° C., and0.050 g (0.286 mmol) of nickel acetate and 0.086 g (0.286 mmol) ofphosphane 6a are added. The reaction mixture is stirred at -30° C. for60 minutes, and then 0.222 g (1.144 mmol) of AgBF₄ are added (P:Ni:BF₄=1:1:4). After another 30 minutes of stirring the solution of styrene isdropwise added within 20 minutes, and ethylene is simultaneouslyintroduced into the apparatus. After 60 minutes the reaction isterminated by introducing gaseous ammonia, the product is condensed offin vacuo, the solvent is withdrawn, and the residue is distilled througha Vigreux column.

Yield: 12 g (46% of theory).

(-)-(R)-3-phenylbutene-1 (75% e.e.); conversion number: 317.

Catalytic Synthesis of Optically Active1-Methyl-2-methylidenecyclopentene EXAMPLE 14

The procedure is as in Example 1 using a 0.5-l four-neck flask. Theflask is charged with about 150 ml of CH₂ Cl₂, and the dropping funnelis filled with 10 g (0.104 mol) of heptadiene-1,6 in about 20 ml of CH₂Cl₂. The solvent is cooled to -30° C., and 0.079 g (0.182 mmol) ofπ-allylnickel chloride/phosphane 6a complex in 15 ml of cooled CH₂ Cl₂and 0.045 ml (0.197 mmol) of Et₃ Al₂ Cl₃ are added. The solution becomesorange in color. The catalyst mixture is stirred at -30° C. for 30minutes, and then the solution of heptadiene-1,6 is dropwise addedwithin 15 minutes. After 3 hours at -30° C. the reaction is stopped withgaseous ammonia. The crude product is condensed off in vacuo, thesolvent is withdrawn, and the residue is distilled through a Vigreuxcolumn.

Yield: 9.4 g (94% of theory).

1-(S)-(+)-1-methyl-2-methylidenecyclopentene, b.p. 96° C.; [α]_(D) ²²+61.6° (undiluted) (93% e.e.); conversion number: 1540

EXAMPLE 15

A 100 l glass reaction vessel equipped with stirrer, a 25-l feed tankand an internal thermometer is provided with an argon atmosphere. Thereaction vessel is charged with 40 l of CH₂ Cl₂, and the feed tank isfilled with 8.26 kg (79.5 mol) of styrene cooled to -20° C. in 16 l ofCH₂ Cl₂. The charged solvent is cooled to -62° C. by means of arefrigerating machine. The liquid is stirred, while 20.3 g (0.047 mol)of π-allylnickel chloride/phosphane 6a complex dissolved in 100 ml ofCH₂ Cl₂ cooled to -60° C. and 25 ml (0.109 mol) of Et₃ Al₂ Cl₃(P:Ni:Al=1:1:4.6) are added. Then ethylene is introduced, and thesolution of styrene cooled to -20° C. by means of a second refrigeratingmachine is allowed to run in within 6 hours. The reaction temperature ismaintained within a range of from -60° C. to -65° C. After 7 hours thereaction is terminated by the introduction of gaseous ammonia. Thesolvent is distilled off under normal pressure, and the residue isfractioned through a column.

Yield: 4.3 kg (32.5 mol; 41% of theory; 87.4% e.e.).

(-)-(R)-3-phenylbutene-1; conversion number: 691.

EXAMPLE 16

The procedure is as in Example 1. A 0.5-l flask is charged with 150 mlof CH₂ Cl₂, and the dropping funnel is filled with 10 g (0.085 mol) of4-methylstyrene in about 40 ml of CH₂ Cl₂. The solvent is cooled to -70°C. with stirring, and 0.109 g (0.25 mmol) of π-allylnickel/phosphane 6acomplex in about 20 ml of CH₂ Cl₂ and 0.115 ml (0.50 mmol) of Et₃ Al₂Cl₃ (P:Ni:Al=1:1:4) are added. At -70° C. the solution of4-methylstyrene is dropwise added within 15 minutes, and ethylene issimultaneously introduced into the solution. The reaction is terminatedby introducing gaseous ammonia, and the reaction mixture is condensedoff in vacuo. The solvent is withdrawn, and the residue is distilled invacuo.

Yield: 11.7 g (94.4% of theory).

(-)-(R)-p-tolylbutene-1); conversion number: 320; [60 ]_(D) ²² -9.89° insubstance (95.2% e.e.).

EXAMPLE 17

The procedure is as in Example 1. A 0.5-l flask is charged with 150 mlof CH₂ Cl₂, and the dropping funnel is filled with 16 g (0.242 mol) ofmonomeric cylopentadiene-1.3 in 15 ml of cooled CH₂ Cl₂. The solvent iscooled to -70° C., and 1.22 g (2.81 mmol) of π-allylnickel/phosphane 6acomplex in 25 ml of cooled CH₂ Cl₂ and 0.353 ml (2.81 mmol) of Et₂ AlClare added (P:Ni:Al=1:1:1). The reaction mixture is stirred at -70° C.for 30 minutes. Then ethylene is introduced into the apparatus for 1minute, and then the solution of cyclopentadiene-1,3 is slowly addeddropwise with simultaneous introduction of ethylene. The addition of thecyclopentadiene-1,3 solution takes 1 hour. Then the reaction mixture wasstirrend for another hour. The reaction is terminated by introducinggaseous ammonia, and the product is condensed off in vacuo. The solventis withdrawn, and the residue is distilled.

Yield: 8 g (0.084 mol; 35% of theory).

(-)-(R)-3-vinylpentene-1 (92% e.e.); conversion number: 30.

EXAMPLE 18

The procedure is as described in Example 16 but using 27.5 g (149,3mmol) 2-methoxy-6-vinylnaphthalene and 0.979 g (2.26 mmol) ofπ-allyl-nickel chloride/phosphane 6a-complex and 0.545 g (4.52 mmol) Et₂AlCl (P:Ni:Al=1:1:2).

Yield: 23.0 g (72.5% of theory) (83.2% ee)

(-)-(R)-2-(6-methoxy-2-naphthyl)-butene-1 (b.p. 104° C./10⁻³ mbar).

EXAMPLE 19

The procedure is as described in Example 16 but using 18.8 g (135.6mmol) 4-chlorstyrene and 498.6 mg (1.15 mmol) of π-allylnickelbromide/-phosphane 6a-complex and 285 mg (1.15 mmol) Et₃ Al₂ Cl₃(P:Ni:Al=1:1:2).

Yield: 22.07 g (97.7% of theory) (95.4% ee)

(-) -(R)-3-(4-chlorophenyl)-butene-1 (b.p. 88° C./14 mbar) (α)_(D) ²⁰-12.716°.

EXAMPLE 20

The procedure is as described in Example 16 but using 40 g (250 mmol)4-isobutylstyrene and 1.05 g (2.43 mmol) of π-allylnickelchloride/-phosphane 6a-complex and 0.56 ml (2.43 mmol) Et₃ Al₂ Cl₃(P:Ni:Al=1:1:2).

Yield: 39.8 g (84.7% of theory) (84.6% ee)

(-)-(R)-3-(4-isobutylphenyl)-butene-1 (b.p. 88° C./5 mbar. (α)_(D) ²⁰=6.18°.

This material can be converted to Ibuprofen, the overall synthesisproceeding as follows: ##STR8##

A similar synthesis can be effected with a benzostyrene, i.e. a vinylnaphthalene, to produce Naproxin which is widely sold, viz.: ##STR9##

EXAMPLE 21

The procedure is as described in Example 16 but using 3.72 g (31.47mmol) 2-methylstyrene and 0.314 g (0.725 mmol) of π-allylnickelchloride/-phosphane 6a-complex and 0.27 g (1.09 mmol) Et₃ Al₂ Cl₃(P:Ni:Al=1:1:3).

Yield: 3.29 g (71.5% of theory) (92.2% ee)

(+) -(R)-3-(2-methylphenyl)-butene-1 (b.p. 58° C./7 mbar).

EXAMPLE 22

The procedure is as described in Example 16 but using 11.7 g (99 mmol)3-methylstyrol and 106.6 mg (0.246 mmol) of π-allylnickelchloride/-phosphane 6a-complex and 61 mg (0.246 mmol) Et₃ Al₂ Cl₃(P:Ni:Al=1:1:2).

Yield: 9.27 g (64.0% of theory) (88.8% ee)

(-)-(R)-3-(3-methylphenyl)-butene-1 (b.p. 80° C./21 mbar).

It will be understood that the specification and examples areillustrative but not limitative of the present invention and that otherembodiments within the spirit and scope of the invention will suggestthemselves to those skilled in the art.

We claim:
 1. In the codimerization of an olefin employing aπ-allylnickel compound as a catalyst, the improvement which comprisesemploying the π-allylnickel compound in the form of a complex withbis-(3R)-3-((1R,5R,8R)-5,9,9-trimethyl-4-[(1R)-1-phenylethyl]-4-aza-5-phosphatricyclo-[6.1.1¹.8.0².6]-dec-2(6)-enyl).
 2. A codimerization according to claim 1, wherein theolefin is a styrene.
 3. A codimerization according to claim 2, whereinthe styrene is a benzostyrene.
 4. A codimerization according to claim 3,wherein the benzostyrene is 2-methoxy-6-vinyl-naphthalene.
 5. Acodimerization according to claim 1, wherein the olefin is an alkylstyrene.
 6. A codimerization according to claim 5, wherein the alkylstyrene is 4-isobutylstyrene.
 7. In the reaction of ethylene withbicycloheptene or a styrene to form optically active vinylbicycloheptaneor 3-phenylbutene-1, the improvement which comprises effecting thereaction in the presence of a π-allylnickel halide/azophospholenecomplex and a Lewis acid.
 8. A process according to claim 7, wherein thestyrene is styrene per se.
 9. A process according to claim 7, whereinthe styrenes is a benzostyrene.
 10. A process according to claim 8,wherein the benzostyrene is 2-methoxy-6-vinyl-naphthalene.
 11. A processaccording to claim 7, wherein the styrene is an alkyl styrene.
 12. Aprocess according to claim 11, wherein the alkyl styrene is4-isobutylstyrene.
 13. A process according to claim 7, wherein the Lewisacid is an alkyl or aryl aluminum halide or BF₄.